Generally, to form a contact between the metal layers of a semiconductor die and a TSV extending through the semiconductor die, a passivation layer overlying the metal layer is etched to form a contact opening and expose a contact portion of the metal line. Subsequent to the etch, a barrier layer is formed to contact the exposed contact portion and cover the sidewalls of both the contact opening and the TSV. The contact opening and the TSV are then subsequently overfilled with copper through a process such as electroplating. While a portion of the copper and barrier layer may be removed, a portion of the barrier layer and copper between the contact opening and the TSV is left in order to maintain an electrical contact, thereby establishing electrical contact to the opposite side of the semiconductor die.
However, this process generally results in a copper conductor that has a low adhesion to the underlying material. Further, because the expanding and contracting caused by process heating and cooling can exacerbate this problem of low adhesion, this also may limit the thermal budgets of later processes that may be needed to finish the manufacturing of the semiconductor die. Such a restriction on subsequent process conditions is undesirable.
Therefore, what is needed is a structure and method by which the TSV temperature capability can be increased by increasing the adhesive capability of the conductor.